This invention relates to modular systems for constructing esthetically pleasing landscaping structures. More particularly it relates to an improved modular landscaping system enabling the custom erection of landscaping edging, walkways, planter boxes, raised-bed gardens, retaining walls, slope terracing, and a wide variety of landscaping structures.
In recent years do-it-yourself landscaping projects have grown in popularity. A properly completed landscaping project can beautify the homeowner's property, magnify the owner's enjoyment of the property, and increase the sale value of the home. Typical landscaping projects involve edging around trees, walks, and drives, and the construction of enclosed planters for flower beds. Some applications require sloped ground to be leveled by terracing which is accomplished by building retaining walls at intervals downhill from one another. The majority of landscaping projects are hampered by the very limited selection of materials available to the homeowner. Common choices for landscaping include railroad cross ties or plywood "peeler cores."
Railroad cross ties are frequently available as "used" ties that have been removed from service by the railroad because of excessive wear or decay. Cross ties are generally six or seven inches thick, eight to nine inches wide, and eight to nine feet long. Their large size, and the fact that they are usually made of hardwood, makes them very heavy and difficult to handle. Cross ties are typically treated with a creosote oil solution that also soils clothing and tools. The standard length of cross ties makes them inconvenient and cumbersome for normal home landscaping projects. For many projects cutting is required. Cross ties are also difficult to join in the corners.
Peeler cores are formed by machining a log section through a veneer lathe. Such cores are typically four to six inches in diameter and eight feet long. Normally the peeler core is sawed full length to remove a small slab along one side, leaving approximately a two inch wide flat surface. This operation is repeated along the opposite side of the peeler core such that the final piece has parallel flat surfaces top and bottom allowing them to be more easily stacked.
Prior art landscaping timbers are usually pressure treated with preservative. Proper treating requires the timber to be kiln dried or air dried to allow for adequate penetration and retention of the preservative. Most often these timbers are not properly dried prior to treatment, and they typically contain a very large percentage of heartwood that will not accept preservative even when properly dried. The resulting product is sold as a "treated wood landscape timber," but it does not carry warranty protection as do most properly treated wood products. Under normal use circumstances where the timber is in direct contact with the earth, the improper treatment generally offers little more life than untreated wood products.
Normal timbers are available in standard lengths of eight feet. Projects needing shorter pieces require that the timber be cut. This difficult task is usually performed with a chain saw and results in breaking the thin envelope of protection provided by the improper treatment. These timbers are deficient when forming corners or angular intersections. They are usually spiked together with large nails, or drilled and linked using pipe or similar materials.
Known prior art patents are as follows:
______________________________________ 1,219,786 Splater Mar. 20, 1917 1,809,508 Colby June 9, 1931 2,687,033 Snyder Aug. 24, 1954 2,951,606 Benson Sep. 6, 1960 3,324,619 Gearhart June 13, 1967 3,487,579 Brettingen Jan. 6, 1970 3,545,128 Fontaine Dec. 8, 1970 3,742,665 Henry July 3, 1973 4,312,606 Sarikelle Jan. 26, 1982 4,353,191 Schilbe Oct. 12, 1982 4,391,077 Giess July 5, 1983 4,433,944 Plica Feb. 28, 1984 4,747,231 Lamay May 31, 1988 4,761,923 Reum Sep. 9, 1988 4,834,585 Hasenwinkle May 30, 1989 4,897,955 Winsor Feb. 6, 1990 4,910,910 Jones Mar. 27, 1990 4,967,526 Yost Nov. 6, 1990 4,997,316 Rose Mar. 5, 1990 ______________________________________
The prior art mentioned above reveals the broad utility concept of a timber locking system. Giess U.S. Pat. No. 4,391,077 teaches the desirability of providing a construction timber with interlocking tongue and grove connectors. The timbers are secured together by locking pins or dowels, and can be linked at various angular dispositions. Earlier patents issued to Snyder and Henry disclose building components provided with notched ends to facilitate interlocking of adjacent logs. The grain tank disclosed by Splater in U.S. Pat. No. 1,219,786 is constructed of a plurality of interlocking timbers, wherein each timber comprises an outwardly projecting end piece or tongue adapted to fit within a corresponding groove. When the boards are connected a pin penetrates locking orifices of the tongues. Similar structure is disclosed by Benson in U.S. Pat. No. 2,951,606.
Weyerhauser U.S. Pat. No. 4,834,585, sets forth drilled landscape timbers that can be angularly disposed relative to one another to form a curved retaining surface. Fontaine U.S. Pat. No. 3,545,128 discloses a corner element that can be coupled to landscape timbers to form corners. Sarikelle U.S. Pat. No. 4,312,606 discloses a retaining wall structure comprised of a plurality of timbers having interlocking post members.
However, the prior art products fail to provide an overall system as described herein which synergistically accomplishes all of the objects and advantages of our system. Peeler core landscape timbers that have been cut and drilled prior to treatment are inconvenient with pins or dowels when stacked. Square timbers have been drilled for attachment in straight lines at ninety degree corners, but they do not provide a workable system that accommodates intermediate angles. None of the known inventions have provided timbers that form connections that allow for any angle of attachment through one hundred eighty degrees of arc.